In a plasma tool, a number of radio frequency (RF) generators are connected to a plasma chamber. The RF generators generate RF signals that may be pulsed and provide the RF signals to the plasma chamber to control various processes in the plasma chamber. A wafer is processed in the plasma chamber by plasma that is generated upon receiving the RF signals and a plasma process gas.
A manner of connecting the RF generators to the plasma chamber varies. For example, some RF generators are connected to a top electrode of the plasma chamber and the remaining RF generators are connected to a bottom electrode of the plasma chamber. Such separate connection help in separate control of the top and bottom electrode. However, the separate control is not cost-effective.
It is in this context that embodiments described in the present disclosure arise.